There is a particular need to protect roof structures from damage by maintenance and other personnel moving thereover, and to assist in ensuring the safety of such personnel. Such needs include also the provision of roof-top fire escape routes. In response to these needs it is well known, particularly for industrial and commercial premises, to construct on a roof top both continuous walkway assemblies, which may be level or slightly inclined, and also series of steps in the form of stairways for movement of personnel over more steeply inclined surfaces or between two levels.
The variety of roof pitch angles and the distances over which a walkway is to be provided has meant that in general bespoke on-site construction work is necessary. However the relative difficulties typically encountered when working in a roof top environment, and exposure to weather, makes it particularly advantageous to provide means for minimising or simplifying the on-site construction work.
Another requirement that needs to be taken into account is that of ensuring that the tread surface does not of itself present a significant safety hazard.
Disadvantages of many known walkway assemblies include difficulty of and time for off-site design work, on-site construction, relative expense, cost of component parts and relatively high weight.